

A026998


Triangular array T read by rows: T(n,k)=t(n,2k), t given by A027960, 0<=k<=n, n >= 0.


19



1, 1, 1, 1, 4, 1, 1, 4, 8, 1, 1, 4, 11, 13, 1, 1, 4, 11, 26, 19, 1, 1, 4, 11, 29, 54, 26, 1, 1, 4, 11, 29, 73, 101, 34, 1, 1, 4, 11, 29, 76, 171, 174, 43, 1, 1, 4, 11, 29, 76, 196, 370, 281, 53, 1, 1, 4, 11, 29, 76, 199, 487, 743, 431, 64, 1, 1, 4
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OFFSET

0,5


COMMENTS

Rightedge columns are polynomials approximating Lucas(2n+1).


LINKS



FORMULA

T(n, k) = Lucas(2n+1) = A002878(n) for 2k<=n, otherwise the (2n2k)th coefficient of the power series for (1+2x)/{(1xx^2)(1x)^(2kn)}.


EXAMPLE

............................1
..........................1,1
........................1,4,1
......................1,4,8,1
..................1,4,11,13,1
...............1,4,11,26,19,1
............1,4,11,29,54,26,1
........1,4,11,29,73,101,34,1
....1,4,11,29,76,171,174,43,1
1,4,11,29,76,196,370,281,53,1


CROSSREFS

This is a bisection of the "Lucas array" A027960, see A027011 for the other bisection.


KEYWORD



AUTHOR



EXTENSIONS



STATUS

approved



